Rotary strainer for a pump



Jan. 14, 1958 J. w. CARTER 2,819,798

ROTARYS'I'RAINER FOR A PUMP Filed Nov. 2 1954 2 Sheets-Sheet 2 2,819,798 ROTARY S'I'RAINER A PUMP J. Warne Garter, Rockdale, Tex.

Application November 2, 1954, Serial No. 466,367

2 (3laims. (Cl. 210-402) The present invention relates to rotary self-cleaning strainers for use on pumps which have special water outlets for a portion of the pump discharge so that water under pressure can be conveyed to the pump shaft bearings for cooling and other purposes.

In many locations the pumps must handle water which is full of leaves, sticks and other trash, and the take-off conduit becomes clogged with annoying frequency. Some pumps are provided with large and complicated strainers on their inlet hose ends, others have strainer boxes adjacent the pump inlet itself.

The present invention has for its principal object to -provide a strainer for the take-off conduit alone, "and one which is automatically cleaned by the rotary movement of the pump shaft.

Another object of the present invention is to provide a strainer of inexpensive construction and one which can be readily attached to the pump shaft with no alteration of the pump casing or shaft.

A further object of the present invention is to provide a strainer which can be mounted on the pump shaft by the use of set screws, and one which is of a size that it can be slipped on the pump shaft from the gland end and in which only a slight alteration of the gland housing need be made in order to accommodate the strainer.

A still further object of the present invention is to provide a strainer of light weight cast or welded construction having a relatively large strainer surface and one which cleans itself by rotary action, a strainer for a pump that is incapable of freezing up separately from the pump, requires no separate lubrication or maintenance, is operable all the time the pump operates and does not require any separate drive or motive power.

These and other objects and advantages of the present invention will be fully apparent from the following description when considered in connection with the annexed drawings, in which:

Figure 1 is a view in elevation of the present invention in place on a pump shaft,

Figure 2 is a side view in cross section on line 22 of Figure 1,

Figure 3 is an end view in cross section on line 33 of Figure 1,

Figure 4 is an end view in cross section on line 4-4 of Figure 2,

Figure 5 is a plan view in elevation of a second embodiment of the invention, and

Figure 6 is an end view in cross section taken on line 66 of Figure 5.

Referring in more detail to the drawing, in which like reference numerals indicate like parts throughout the several views, the invention will be seen to consist of a cast iron, aluminum or brass perforated sleeve 10 having a closed end 11 and an integral concentrically disposed inner bushing 12. The sleeve 10 diverges outwardly from the closed end 11 to the open end 13, the bushing 12 tapering inwardly to its end 14 which is at a spaced dis- 2,819,798 Patented Jan. 14, 1958 tance inwardly from the open end 13 of the sleeve. The closed end 11 of the sleeve 10 has its end face 15 sloping outwardly from the outer edge toward the center. Set screws 16 secure the sleeve to the pump shaft 17 immediately adjacent the inner end 18 of the gland housing 19 which is removably secured in one wall of the pump casing, the impeller, other walls, and other elements of the pump not being described or illustrated here as not a part of the invention.

The pump shaft 17, in a conventional construction as here illustrated, is supported by a bronze bushing 21 press fitted into a bore 22 in the gland housing 19, the bore being enlarged at its outer end to receive the gland .packing 23, usually made of graphite impregnated asbestos rope or other self lubricating watertight material. The bore 22 is threaded at its outer end to receive the gland nut 24. The gland housing 19 is here shown as having external threads 25 to engage the threads in the opening 27 in the wall 20, although in some forms of construction the housing is non-circular and is bolted to the housing, with a suitable gasket between. A gasket 28 is shown in the present embodiment and a second bore 29 of relatively small diameter extends from one end of the housing to the other to form a conduit for water to cool the bearings of the pumps, not here shown, the bore 29 being internally threaded to receive a pipe leading to such bearings.

The inner end 18 of the housing 19 is undercut on its outer edge 32 in order to receive in close tolerance the inner edge 33 of the open end 13 of the sleeve 10, this undercutting being essential to smooth the otherwise irregular outer end edge of the housing which is usually of gray iron or of a material not ordinarily machined.

In another embodiment of the invention illustrated in Figures and 6, the details of construction of the sleeve are the same, but the sleeve 34 is of cylindrical shape and is covered with a wire mesh screen 35, the sleeve being slotted from near one end to near the other and being fitted at one end with an annular plate 36, the inner edge of which is welded on one end of a bushing 37. Set screws 38 secure the bushing to the pump shaft 17, and the other end of the sleeve 35 is fitted with a second annular plate 39 in which are equidistantly spaced holes 40. The second annular plate is spaced inwardly a short spaced distance from the other end of the sleeve 34, at such a distance that the plate 39 is a short distance from the inner end 18 of the gland housing and serves to support the strainer concentrically on the shaft, the water flowing through the holes 40.

The net effect of each embodiment is the same, the second embodiment being found to strain more water but being of lighter material and welded in its assembly it may not stand up under the excessive rough usage as does the cast form as in the prior embodiment. In each case, the opening into the wall which is taken up by the gland housing is considered when the dimensions of the sleeves or 34 are to be determined, it being a feature that the strainer of this invention may be inserted through this opening with the gland housing removed, as a very expedient and economical method of assembly.

In operation of the form of Figures 1 to 4, the water containing leaves, stalks and trash which is in the space surrounding the pump shaft 17 is subjected to the action of the strainer or sleeve resulting in the strainer arresting the egress therethrough of the leaves, stalks and trash and permitting only the water freed thereof to flow through the perforations into the space between the sleeve and the pump shaft. The thus freed water in the space between the sleeve 10 and the pump shaft 17 flows upwardly through the bore 29 in the gland housing 19 and thence into pipe 31 through which it is conveyed to the point for cooling the bearings of the pump. The water in the space exteriorly of the strainer and containing the debris aforementioned, is discharged out of the discharge end of the pump, not shown.

In the operation of the form of Figures 5 and 6, the water containing leaves, stalks and trash which is in the space surrounding the strainer or sleeve 34 is subjected to the action of the strainer or sleeve 34, resulting in the strainer arresting the egress therethrough of the leaves, stalks and trash and permitting only the water freed thereof to flow through the perforations into the space between the sleeve 35 and the pump shaft 17. The water in the space between the sleeve 35 and the pump shaft 17 flows upwardly through the perforations in the plate 29 and thence into the bore in the gland housing and into the pipe 31, which conveys it to the point for cooling of the bearings of the pump. Here also, the water containing the above noted debris in the space surrounding the sleeve 35 is discharged through the discharge end of the pump, not shown.

While only preferred embodiments of the present invention have been here illustrated and described, other em bodiments may be made and practiced and many changes and alterations in the form and construction may be made within the scope of the appended claims without departing from the spirit of the invention.

It is an important feature of the invention that the strainer area be carefully designed with relation to the quantity of water to be strained so that the pressure drop through the strainer be kept to the minimum so that the strainer be self-cleaning. Otherwise the centrifugal force would be insufficient to keep the strainer clean.

What is claimed is:

1. The combination with a rotatable pump shaft, of a perforated sleeve surrounding and spaced from said shaft and secured to said shaft, said sleeve having one end closed and having the other end open, and a gland housing circumposed about and carried by said shaft and having one end closing the open end of said sleeve, there being a bore in said housing extending from said one end to the other end and having the end adjacent said one housing end in communication with the open end of said sleeve, and means on the other end of the bore for receiving water from said bore.

2. The combination with a rotatable pump shaft, of a perforated sleeve surrounding and spaced from said shaft and secured to said shaft, said sleeve having one end closed and having the other end open with a wall diverging outwardly from the closed to the open end, and a gland housing circumposed about and carried by said References Cited in the file of this patent UNITED STATES PATENTS 336,807 Hawley Feb. 23, 1886 350,362 Hawley Oct. 1886 1,473,667 Burks Nov. 13, 1923 1,578,720 Derby Mar. 30, 1926 2,243,585 Towler et a1. May 27, 1941 2,420,592 Gerhardt May 13, 1947 

